<!DOCTYPE html>
<html>

<head>
  <meta charset="UTF-8">
  <title>学习表格标签</title>
</head>

<body>
<table border="1">
  <caption>前端三剑客</caption>
  <tr>
    <th>知识点</th>
    <th>重要程度</th>
    <th>难度</th>
    <th>学习周期</th>
  </tr>
  <tr>
    <td>html</td>
    <td>5星</td>
    <td>3星</td>
    <td>7天</td>
  </tr>
  <tr>
    <td>css</td>
    <td>5星</td>
    <td>4星</td>
    <td>10天</td>
  </tr>
  <tr>
    <td>js</td>
    <td>5星</td>
    <td>5星</td>
    <td>20天</td>
  </tr>
</table>
</body>

</html>